Method for the production of filaments and fabrics from fluids



Dec. 23, 1947. F. w. MANNING )METHOD FOR THE PRODUCTION OF FILAMENTS ANDFABRICS FROM FLUIOS Filed Sept. 29, 1945 Hum I.. wm. WN N .Mn www mahNL' mm, Numb/vl.

w. a im Patented Dec. 23, 1947 UNITED STATES PATENT oFFlcE METHOD FORTHE PRODUCTION OF FILA- MENTS AND FABRICS FROM FLUIDS Fred w. Manning,relu Alto, cam.

Application September 29, 1943, Serial No. 504,524

, 423.733,. subsequently issued as Patents Nos.

2,336,743, 2,336,744, and 2,336,745, respectively.

Prior practice has been to limit the use of spray guns to the disruptionof substances into droplets, which were projected against surfaces wherethey flattened out into overlapping scales and then became induratedinto hardened coverings, but as far as I am aware, no attempt has everbeen made to use a spray gun to attenuate a fluid into a plurality offilaments, and disperse and deposit the filaments to form a non-wovenfabric.

It is therefore the primary object of my invention to provide aninexpensive method for disrupting a fluid into a plurality of filaments,and projecting the filaments in an adhesive state upon the object to becoated or covered by intersectlng filaments. 'Such a non-woven fabriccan then be sprayed by droplets to form a film thereover, which coatingmay cover the filaments alone to protect the latter and leave the fabricpervious, or the film may also cover the interstices and leave thefabric impervious, or the film covering for filaments and/or intersticesmay leave the fabric pervious to certain fluids and impervious to otheruids. These composite fabrics may then be sprayed by treating fluids orsolids in finely divided form.

In accordance with my invention, I propose to use spinning materialswhich are usually thermoplastic but may be thermosetting. A greatvariety of plastics may be used for as many different purposes, suchasvinylidene chloride, vinyl chloride acetate, polyvinyl chloride,polyvinyl butyral, polystyrene, polyvinyl acetate, methyl methacrylate,and polymeric amide resins, ureaformaldehyde and phenol-formaldehydecompounds, latex compositions, cellulosic and petroleum derivatives,protein-base materials, glass, mixtures of organic and inorganicmaterials, and almost all materials that are now spun or extruded intolments, films and foils. These materials may be reduced to a fluidcondition by means of solvents, pressure, heat, or any combination ofthese three treatments. Acetone may be used as a solvent for celluloseacetate, phenol and formic acid for a polymeric amide,

toluene for a copolymer of vinyl acetate andv 3 Claims. (Cl. 154-101.)

4 Vusually prefer to reduce a plastic to a fluid state water from thespun filaments.

by heat treatment, with or without a moderate amount of solvent to lowerthe softening point of the plastic, or else by using a solvent that isvery cheap. Preferred solutions for'many purposes are aqueous lsolutions of polymerized vinyl alcohol. The amount of polyvinyl alcoholrequired in a water solution for spinning purposes may be as low as 5per cent by weight, or it may be as much as 25 per cent, or more, and asmall amount of acetone, alcohol, etc., may be added to the solution tospeed the evaporation of the The solution may be heated to the boilingpoint o f water in an open vessel, or a4 much higher temperature underpressure in a closed container, and during the spinning of the filamentsthe latter may be subjected to a blast of hot air to hasten theevaporation of the water.

An elastic or liquid fluid blast or stream may be used in the gun fordisrupting a plastic fluid into a plurality of filaments, and mayenvelop, or be positioned adjacent to, the filaments to propel them at amuch greater speed than their extrusion speed in order to attenuate thefilaments and orient their molecular structure. A secondary fluid blastor stream may envelop, or be positioned adjacent to, the first andtravel at a still greater velocity to give the filaments additionalstretch or accelerate the stretching operation, and either or both maybe also used for conveyance, induration, dispersion, disruption, anddeposition, of the filaments. Heated air, or superheated or saturatedsteam, may be used for maintaining the filaments in a plastic conditionuntil deposited, or vfor removing a volatile solvent from the filamentsbefore or/and after deposition; cold air, a cold water spray carried byan elastic fluid, or a cold water stream, may be used for quenching orshrinking the laments during conveyance or after deposition,

and for other induration purposes; non-oxidizing fluids, such as helium,nitrogen, hydrogen, argon, or carbon dioxide, may be used whereoxidation tendsto discolor or decompose the filaments; and any of theabove fluids may be used to convey treating agents in a finely dividedform, such as adhesives or solvents to bond indurated filamentstogether, pigments to color the filaments, water repellents, fireretardants, wetting agents, lacquers, etc.

Any pressure fluid for the above mentioned purposes may also be used toactuate a motor for driving a centrifuge or other mechanism to speed upthe operations for which treating fluids are used, such as thedisruption of a. plastic i'iuid into a plurality of nlaments, stretchingof the laments, etc. The spinning material may be fed into a centrifugethrough a rotating shaft that connects the motor to the centrifuge, orthrough a fixed tube within the rotating shaft, or through a tubepositioned externally of the shaft. The disruption of the material bycentrifugal force through suitable openings in the perimeter of thecentrifuge, which may be aided by a primary blast or stream of elasticor liquid fluid intermixed with the filaments, will result in rapidlywhirling filaments within deecting walls that will change the spirallingmovement of the filaments to a helicoidal movement directed toward theobject to be covered; or the spirallng of the filaments with or withoutthe aid of the primary blast or stream may be changed to an advancinghelicoidal movement by an enveloping secondary stream of an elastic orliquid fluid, directed toward the object to be covered and lin the samecontrolled path. And, of course, 'the plastic fluid may be disruptedinto filaments through openings in an extrusion device by a pressuredifferential, and the filaments propelled through a controlled path anddeposited by either, or both, primary and secondary conveying fluidswithout aid of centrifugal force. The length of the filaments atdeposition will depend on the extent they are subjected to opposingforces during conveyance and stretching, kind of plastic, etc. 'Ihey maybe stretched and .deposited in substantially continuous lengths and in auniformly intersected condition, with or without aid from the conveyingiluids,by reciprocating, rotative, or other regular movements of eitheror both gun and object being coated; or they may be deposited in brokenlengths in a promiscuously intersected condition, in which case theactual lengths of the laments in an integral fabric will seldom beapparent.

Any suitable means may be utilized to create the differential pressurerequired to feed the plastic iiuid from a supply container to thecentrifuge, such as fluid pressure exerted within the, container, orwithdrawal of atmospheric pressure ning operation will cause bubbles toform within the filaments.

The invention is exemplified in the following description, and apreferred arrangement is illustrated by way of example in theaccompanying drawings, in which:

Figure 1 is a vertical section of a spinning gun.

Figure 2 is a cross-section taken on line 2-2 of the gun.

Figure 3 is an elevation view of the end of the spinning gun and aretaining wall for the spun which are threaded into the stock: andbetween the two is an annular shaft 4, which is driven I by a rotor orturbine 5 and .supported by the ball bearings .8 and l; and the latterare enclosed within a tube 8 that is concentric with the gun barrel andspaced therefrom by means of ribs 9 to allow for escape of the exhaustfrom the rotor. A heating element I0, which is placed between mica tubesI l and I2 and enclosed within another tube I3, surrounds the barrel,and the temperature of the element is regulated by the thermostat i4.The inner conical portion It of the extrusion nozzle or centrifuge isadjustable on the end of the turbine shaft in order that the conicalportion I6 of the tube I1 may be used to regulate the air blast to thecentrifuge; and both portions of the centrifuge are united by radialribs i8, the spacing of which determines the area of the plastic streamsthrown oif by centrifugal force. Air pressure from any suitable sourceof supply enters the stock at i9, and the flow of air to duct 20 iscontrolled by valve 2|, which is held in normal closed position by aspring 22 and plug Z3, the valve being operated by a, trigger 213supported on a pin 25. The supply of air through duct 26 to the chamber2l is regulated by an adjusting screw 28 within the packing nut 29; theair supplyy from the chamber to the centrifuge is regulated byadjustment of the latter on the turbine shaft, as mentioned above; andthe air supply from the chamber to the turbine is regulated by anadjusting screw 30 within the packing nut 3l, the latter screwcontrolling an opening 32 placed at a, suitable angle for driving thebuckets or blades of the turbine. The solution is held in container 33,which is connected to the feed tube'by container cap 36, lock nut 35,fitting 36, and passage 31, the latter being regulated by an adjustingscrew 38 within the packing nut 39. An electric wire enters the gunstock at 40, and makes the circuit to the thermostat and heating elementthrough ducts 4I, d2 and 43. A pressure uid may be applied to thecontainer through pipe connection M.

Figure 3 shows a basket of fruit 55, over which is spun a web 46 ofpromiscuously intersecting filaments, the mesh being sufficiently fineand transparent to prevent infiltration of dust particles whilepermitting respiration and inspection. And, as indicated above, such acovering may be sprayed with a suitable impregnant to make the formerimpervious to moisture, as when the former is spun over a gun.

The operation of the apparatus thus described has been in part indicatedin connection with the foregoing description. The rapid rotation of anextrusion device will always tend to whirl the filaments at right anglesto the axis of rotation, unless the filaments are diverted by defiectingwalls or movement of a fluid in an opposing direction. In the aboveillustration, the spinning fluid is conveyed by a differential pressurethrough a stationary feed tube into a centrifuge and there disrupted andconveyed by the joint action of centrifugal force and a blast of elasticfluid moving both spirally and helically between defiecting walls untilfinally the laments are carried into the path of the exhaust fluid fromthe motor, upon which both fiuids unite and are directed through the gunbarrel for dispersion and deposition purposes. If maximum stretch isrequired for the filaments, not only should the velocity of theconveying fluids be high, but both extrusion tube Il and gun barrel 2should be of substantial length as from one to six feet; if littlestretch is required, the gun barrel must project at least a shortdistance beyond the point at which the filaments are thrown from thecentrifuge in order that a, controlled path be provided for directingthe deposition of the filaments.

If thev spinning solution is fed through an extrusion device at roomtemperature, the heating element may be used to raise the temperature ofthe motor exhaust iluidin order that the latter may remove moreeffectively the solvent from the extruded laments, prevent adherence ofthe filaments to the gun barrel, etc.; if the solution is fed throughthe extrusion device in a heated condition and the filaments arerequired to be cold drawn, a quenching or shrinking iluid, such as coldair, cold water, cold oil, etc., may be used to drive the motor andstretch the filaments, in which case the heating element may or may notbe required.

A partial indurat'ion of the filaments will take place within the gunbarrel, but it is usually desirable that the filaments be deposited in asufficiently plastic state to adhere to one another in an intersectedcondition upon deposition to form an integral fabric, and the indurationbe completed thereafter. However, it will be obvious that they can alsobe deposited in a hardened and discrete condition, and 'the bonding beaccomplished simultaneously with deposition, or thereafter, by anadhesive or solvent spray from another gun.

It will also be evident that hot or cold liquids may be substituted forelastic iiuids for coagulating, stretching, conveying, and depositingthe filaments, and also to provide an actuating force for driving themotor. However, dry spinning elastic uids will usually be foundpreferable for most purposes, and induration can be speeded and thestretching increased by a rapid whirling of the illaments beforedeposition. which may be accomplished by whirling them in spirals andthen in helices, or the two movements may be combined as a resultant ofopposing forces.

I claim:

1. The method of producing anon-woven fabric comprising: disrupting aplastic material into a plurality of filaments by the joint action o!centrifugal force and a blast 'of an elastic Primary fluid moving ata'given speed; enclosing the said filaments and said primary fluidwithin a concentric blast oi an elastic secondary fluid moving at agreater than the said given speed; maintaining the'said fluids in auniformly heated condition during the said movements: and depositingcomprising: disrupting a plastic material into a plurality of filamentsby the joint action of centrifugal force and a. blast of' elasticprimary fluid moving at a given speed; enclosing the said laments andsaid primary fluid within a propelling blast of an elastic secondary uidmoving at a greater speed than the said given speed; maintaining thesaid fluids in a uniformly heated condition during the said movements;and depositing the said laments, while sufficiently plastic to adhere toone another, upon a retaining wall in such a manner as to cause theiilaments to intersect and unite into an integral web.

3. 'I'he method of producing a non-woven fabric comprising: disruptingav plastic material into a plurality of filaments by the joint action ofcentrifugal force and a blast of elastic primary fluid; enclosing thesaid laments and said primary fluid within a, concentric blast of auniformly heated elastic secondary uid; projecting the said filaments bythe propelling actionof the two said fluids so as to deposit thelaments, while sumciently plastic to adhere to one another, upon aretaining wall in such a manner as to cause the filaments to intersectand'unite into an integral web.

FRED W. MANNING.

REFERENCES CITED The following references are of record in the me ofthis patent:

UNITED STATES PATENTS Hooper July 8, 1924

